Are we talking “How far can you see” or How far away an object has to be,
and still be recognizable ? You can see Jupiter quite clearly in the
evening sky, but if you didn’t know what it was, you would think it was just
another bright star, and that is relatively close to us.
Parameters need to be set, to give an accurate answer
I believe at sea, you can see about 20miles to the horizon. I think this is
one of those subject which could start to get rather “heavy”. 